Sony Xperia X Premium could pump up the brightness with an HDR screen

All the colours of the rainbow

The Sony Xperia Z5 Premium was the world's first 4K smartphone, and it looks like Sony could be working on another smartphone screen-first, as an upcoming handset is rumoured to have an HDR screen.

The phone, apparently dubbed the Xperia X Premium, would presumably slot in above the Xperia X Performance in Sony's upcoming range and would supposedly be able to display 1.07 billion different colours, up from the 16.8 million offered by current smartphones.

It would manage this by offering 1024 different shades of red, blue and green, instead of the standard 256 shades.

Other highlights include a 120Hz refresh rate, 2000:1 contrast ratio and up to 1300 nits of brightness - the blazingly bright Samsung Galaxy S7 tops out at a mere 855 nits.

There could be a catch

The upshot of all this is that it should be a hugely impressive screen, although the 4K resolution on the Sony Xperia Z5 Premium was only on tap for a limited selection of content, so there's the worry that there could be a similar catch here.

Then there's the source. This rumour comes from unnamed sources speaking to PhoneRadar, which doesn't have much of a leakage history, so we'd take it with the usual pinch of salt.

Even if it does pan out, the Sony Xperia X Premium might disappoint in other ways. It supposedly has a 5.5-inch screen, a Snapdragon 820 processor and an Adreno 530 GPU, but just 3GB of RAM and a 1080p resolution, both of which are a step down from most 2016 flagships.